PROJECT SUMMARY/ABSTRACT Juvenile justice (JJ) is the public service system most impacted by alcohol and other drug (AOD) use in youth, and outcomes for these youth, their families, and society are grave. Thus, delivery of effective interventions with JJ youth is of considerable importance. The evidence-based practices (EBPs) with the strongest outcomes for JJ youth are family-based, but many communities do not have the resources to support their delivery. This is particularly true in rural areas where AOD treatment resources are scarce. Further, even when communities can support a family-based EBP, JJ youth face barriers to treatment participation. Indeed, JJ youth are routinely referred for treatment, but data indicate less than 1 in 5 actually receive treatment. Juvenile probation/parole officers (JPOs) are on the front line of this crisis. This workforce is in every community across the nation and routinely interfaces with JJ youth to try to achieve positive outcomes. However, JPOs often face limited options for treatment referrals; further, they do not have the time or training to deliver one of the full-scale, family-based EBPs. As a consequence, JPOs try to manage the behavior of their probationers with a small menu of youth-based interventions that have limited success (e.g., structured sanctions). One strategy for achieving better outcomes in low-resourced, rural settings that cannot deploy a full-scale EBP, called task-shifting, involves redistribution of tasks downstream to an indigenous workforce that has less training. Importantly, reviews indicate that the leading EBPs for JJ youth share a common change mechanism: activation of parents. Thus, while the family-based EBPs cannot be task-shifted, perhaps the central change mechanism of these EBPs (parent activation) can be shifted downstream to enhance JPO practice. JJ leaders already cite improved parent engagement as a top priority, but it is also one of the most challenging problems facing the JJ system. Fortuitously, within pediatric healthcare services, there is an effective intervention called parent activation (PA) comprised of concrete tasks by healthcare service providers to better engage and motivate parents of at-risk youth. PA has been delivered by clinicians and also by paraprofessionals. Thus, this healthcare service advance might be primed for use by JPOs to activate parents and achieve more positive JJ youth outcomes. The proposed stepped-wedge cluster randomized trial investigates the use and impact of PA by JPOs across 32 rural counties. Aims are to: (1) determine the capacity of JPOs to deliver PA within JJ services, (2) examine impact of PA delivery on de-identified family outcomes, and (3) examine implementation outcomes, assessed via the Stages of Implementation Completion, for PA in the JJ service system, including JPO inner context variables that might impact implementation. In a context where the nation?s behavioral healthcare service system is struggling to meet the needs of JJ youth, JPOs across the nation, and particularly in rural communities, are positioned to make a large impact via use of an advance from pediatric healthcare services.